The Rebels fought back well after falling behind early on Tuesday night, but looked lightweight up front as they pressed for a second-half winner.
Manager Graham Roberts must surely now step up his search for the quality striker who could help Slough to turn this kind of game into three points.
With only four minutes gone, the home side were stunned by a spectacular opener from Hendon midfielder Freddie Hyatt.
The Slough defence failed to clear a corner and Hyatt speared a magnificent drive into Paul Wilkerson's net via the crossbar.
But the industrious Youness Nabil earned the Rebels a chance to equalise as he cut inside from the left, only to be brought down by Jason McKoy.
Defender Al-James Hannigan took responsibility for the spot-kick and struck his shot well enough, but Hendon keeper Gary McCann pulled off a superb save, diving to his left.
A horrendous blunder by Wilkerson at the other end almost put Hendon two up as he placed a soft clearance at the feet of Dominic Gentle, but managed to get across to block the shot with his legs.
And the teams were all square two minutes later when Mark Hawthorne forced his way into the Hendon penalty area.
He picked out Paul Barrowcliff, who had made a good surging run into the box and beat McCann with a left-foot shot.
Slough could have gone in front before half-time, with Hannigan blasting a drive just past the post and Chris White glancing a header off target.
The balance of power fluctuated after the break and Nabil nearly scored a sensational second for Slough with a moment of genius.
Racing onto a long ball out of defence, he held off his markers to strike a confident 35-yard chip which had McCann backpedalling desperately to tip it over the bar.
Wilkerson saved a low effort from Hendon centre-forward Mavuto Sakala and was then relieved to see Gentle live up to his name with a tame shot which was easily smothered.
Roberts brought on Mark Pye to stiffen the midfield, but a stalemate gradually developed, with both sides restricted to long-range shots.
Hyatt came close to snatching the winner for Hendon when Wilkerson had to turn his swerving free-kick over the bar.
And, in injury time, man of the match Mark Hawthorne was foiled by Jon Daly's challenge as he shaped up for a shot on goal.
Hendon Line up
Gary McCann, Matthew Maran, Simon Clarke, Jon Daly, Paul Towler, John-Simon White, Gary Fitzgerald, Freddie Hyatt, Mavuto Sakala, Jason McKoy, Dominic Gentle. Subs: Dale Binns (for Sakala), Marvyn Watson, Bontcho Guentchev (for Gentle).